Cable-to-Card Connectors
The workstation and personal computer market drives numerous manufacturers to provide specialized Add-On cards, called Adapter Cards, aimed at providing specific functions and attachments to various networks, computers, peripherals, and other systems (called External Devices). Many of these Adapter Cards are equipped with large Input/Output (I/O) connectors for transmitting to said External Devices the high number of signals often used by today applications. Most workstations, personal computers or other systems (called Host Machines) provide one or more slots for plugging Adapter Cards. A slot consists of free room in the host machine housing (also called chassis), associated with:
an Adapter Card, PA1 electrical means (called Card Connector) for connecting the Adapter Card with the host machine circuitry, and PA1 an opening in the host machine housing for plugging an external Cable Connector to the Adapter Card. PA1 National and International Authorities progressively enforce regulations on Electro Magnetic Compatibility (EMC) and the specifications are more and more stringent. PA1 The mechanical interface between Adapter Card and External Device must fit with all existing and future machines of a given type or family and must follow all relevant specifications, including design points not adapted any more to the performance improvements of current products. PA1 Generation of an Electro Magnetic Interference (EMI) capable of disturbing other devices in the vicinity (TV, AM/FM), PA1 Increase of the Electro Magnetic Interference (EMI) susceptibility to external electromagnetic fields created by intentional emitters (Radio, TV, GSM, . . . ) or by non intentional sources (Car ignition, Electrostatic Discharges, coupling with noisy cables, . . . ) PA1 Vertical Slots: When the Cable Connector is plugged in to the Adapter Card Connector, the output cable is primarily sensitive to horizontal impacts and constrains. This happens more particularly during the installation, configuration or maintenance of the host machine; PA1 Horizontal Slots: When the Cable Connector is plugged in to the Adapter Card Connector, the output cable is primarily sensitive to vertical impacts and constrains, said constrains being amplified by the weight of the cable assembly. PA1 The lower edge of Bracket (101) is pushed apart from the chassis of the host machine (105) reducing the space (dl, 107) between the chassis (105) and the bottom of the front portion of the Cable Connector (103). This mechanical constraint creates an interval or an air gap (108) between the Adapter Card Bracket (101) and the chassis (105) which dramatically impairs the electromagnetic properties of the assembly. PA1 The Adapter Circuit Board (109) is bent within the host machine which creates a potential source of failure. PA1 a host machine chassis comprising at least one slot card connector mounted therein and at least one slot opening; PA1 an adapter card mounted in said at least one slot card connector inside said host machine chassis, said adapter card being assembled with: PA1 a cable connector comprising a terminal part with electrical contacts to be inserted through the slot opening in said card adapter connector.
Electrical and mechanical characteristics of host machines slots as well as corresponding Adapter Cards are defined by diverse industry standards (ISA, EISA, Microchannel, PCI and others) which all have the same structure as far as Input/Output connector is concerned. As shown in FIG. 1, the Adapter Card Connector (102) is electrically and mechanically fastened to the Adapter Card Printed Circuit Board (PCB) (109). A Bracket (101) is assembled with the connector (102). The external Cable Connector (103) is fastened to the bracket by a pair of screws (104, 110) or other fastening means. The function of the Bracket is to obturate the slot opening (111) when the Adapter Card is slid into the host machine slot while having access to the Adapter Card Connector (102) from outside. The Bracket may include screws, groove and tongue joints or other fasteners depending on the different standards, for securing the Adapter Card in place in the slot. In addition to obvious safe and efficient operations, Adapter Cards have to comply with various standards:
Electro Magnetic Compatibility (EMC)
The assembly shown in FIG. 2 and comprising Cable Connector (103) and the Adapter Card Connectors (102), must provide an efficient containment of the Electro Magnetic Interference (EMI) and Radio Frequency Interference (RFI) within the host machine housing. At Adapter Card level, shielding continuity is ensured by the mechanical contact between the host machine chassis (105) and the shield of the Adapter Card Connector (102) through Bracket (101). Maximum shield efficiency is obtained when said contact is realized all around the connector (102), otherwise inner currents of the shield are mixed with outer currents and the following problems may occur:
Consequently, an Adapter Card Connector (102), once installed, must be in contact with the Chassis (105) of the host machine, regardless of the mechanical efforts to which this connector is exposed to.
Mechanical Constrains
Depending on host machine design, slots can be either vertical or horizontal; so Adapter cards can be installed vertically or horizontally. Mechanical problems may occur in both cases:
Although the claimed invention can be used in both configurations, the configuration with horizontal Slots is the most sensitive.
Connector Installation
By construction, Adapter Card Brackets (10l) and Adapter Card Connector (102) are fixed together as shown in FIGS. 2 and 3. The Cable Connector (103) is inserted in the Adapter Card Connector (102) and both are fastened together by means of one or a plurality of locking screws (104). As detailed in FIG. 4, the vertical force applied downwards to the Cable Connector (103) creates a torsion force at the contact point (112) of the host machine chassis (105) with the upper edge of the Bracket (101). This results in a rotational movement of the overall assembly around point (112):